Cyclomatic complexity for index is too high. [9/6] Open
def index
current_program.build_project_anchor unless current_project_anchor
@project = current_program.project_anchor.projects.build unless current_project(
raise_if_published: false
)
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This cop checks that the cyclomatic complexity of methods is not higher than the configured maximum. The cyclomatic complexity is the number of linearly independent paths through a method. The algorithm counts decision points and adds one.
An if statement (or unless or ?:) increases the complexity by one. An else branch does not, since it doesn't add a decision point. The && operator (or keyword and) can be converted to a nested if statement, and ||/or is shorthand for a sequence of ifs, so they also add one. Loops can be said to have an exit condition, so they add one.
Method has too many lines. [13/10] Open
def index
current_program.build_project_anchor unless current_project_anchor
@project = current_program.project_anchor.projects.build unless current_project(
raise_if_published: false
)
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This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.
Perceived complexity for index is too high. [9/7] Open
def index
current_program.build_project_anchor unless current_project_anchor
@project = current_program.project_anchor.projects.build unless current_project(
raise_if_published: false
)
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- Exclude checks
This cop tries to produce a complexity score that's a measure of the
complexity the reader experiences when looking at a method. For that
reason it considers when
nodes as something that doesn't add as much
complexity as an if
or a &&
. Except if it's one of those special
case
/when
constructs where there's no expression after case
. Then
the cop treats it as an if
/elsif
/elsif
... and lets all the when
nodes count. In contrast to the CyclomaticComplexity cop, this cop
considers else
nodes as adding complexity.
Example:
def my_method # 1
if cond # 1
case var # 2 (0.8 + 4 * 0.2, rounded)
when 1 then func_one
when 2 then func_two
when 3 then func_three
when 4..10 then func_other
end
else # 1
do_something until a && b # 2
end # ===
end # 7 complexity points
Method index
has a Cognitive Complexity of 11 (exceeds 5 allowed). Consider refactoring. Open
def index
current_program.build_project_anchor unless current_project_anchor
@project = current_program.project_anchor.projects.build unless current_project(
raise_if_published: false
)
- Read upRead up
Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Missing magic comment # frozen_string_literal: true
. Open
class Setup
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This cop is designed to help upgrade to after Ruby 3.0. It will add the
comment # frozen_string_literal: true
to the top of files to
enable frozen string literals. Frozen string literals may be default
after Ruby 3.0. The comment will be added below a shebang and encoding
comment. The frozen string literal comment is only valid in Ruby 2.3+.
Example: EnforcedStyle: always (default)
# The `always` style will always add the frozen string literal comment
# to a file, regardless of the Ruby version or if `freeze` or `<<` are
# called on a string literal.
# bad
module Bar
# ...
end
# good
# frozen_string_literal: true
module Bar
# ...
end
Example: EnforcedStyle: never
# The `never` will enforce that the frozen string literal comment does
# not exist in a file.
# bad
# frozen_string_literal: true
module Baz
# ...
end
# good
module Baz
# ...
end
Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
if current_project_anchor && current_project_anchor.project && params[:project_id]
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This cop transforms usages of a method call safeguarded by a non nil
check for the variable whose method is being called to
safe navigation (&.
). If there is a method chain, all of the methods
in the chain need to be checked for safety, and all of the methods will
need to be changed to use safe navigation. We have limited the cop to
not register an offense for method chains that exceed 2 methods.
Configuration option: ConvertCodeThatCanStartToReturnNil
The default for this is false
. When configured to true
, this will
check for code in the format !foo.nil? && foo.bar
. As it is written,
the return of this code is limited to false
and whatever the return
of the method is. If this is converted to safe navigation,
foo&.bar
can start returning nil
as well as what the method
returns.
Example:
# bad
foo.bar if foo
foo.bar.baz if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
foo && foo.bar
foo && foo.bar.baz
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar&.baz
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo && foo.bar.baz.qux # method chain with more than 2 methods
foo && foo.nil? # method that `nil` responds to
# Method calls that do not use `.`
foo && foo < bar
foo < bar if foo
# This could start returning `nil` as well as the return of the method
foo.nil? || foo.bar
!foo || foo.bar
# Methods that are used on assignment, arithmetic operation or
# comparison should not be converted to use safe navigation
foo.baz = bar if foo
foo.baz + bar if foo
foo.bar > 2 if foo